Impact of Fungicide Seed Treatments on Rhizoctonia Root Rot, Take-all, Eyespot, and Growth of Winter Wheat

Plant Disease ◽  
1990 ◽  
Vol 74 (10) ◽  
pp. 782 ◽  
Author(s):  
R. W. Smiley
Keyword(s):  
Winter Wheat ◽  
Root Rot ◽  
Seed Treatments ◽  
Rhizoctonia Root Rot ◽  
Take All

scholarly journals Yield Responses of Direct-Seeded Wheat to Rhizobacteria and Fungicide Seed Treatments

Plant Disease ◽  
2002 ◽  
Vol 86 (7) ◽  
pp. 780-784 ◽  
Author(s):  
R. James Cook ◽  
David M. Weller ◽  
Adel Youssef El-Banna ◽  
Dan Vakoch ◽  
Hao Zhang
Keyword(s):  
Spring Wheat ◽  
Root Rot ◽  
Soil Fumigation ◽  
Seed Treatments ◽  
Root Diseases ◽  
Pythium Root Rot ◽  
Rhizoctonia Root Rot ◽  
Direct Seeded ◽  
Yield Responses ◽  
Take All

Field trials were conducted with winter and spring wheat in eastern Washington and northern Idaho over several years to determine the benefit, as measured by grain yield, of seed treatments with rhizobacteria and formulated fungicides in cropping systems favorable to root diseases. The trials were conducted with wheat direct-seeded (no-till) in fields with a history of intensive cereals and one or more of the root diseases: take-all caused by Gaeumannomyces graminis var. tritici, Rhizoctonia root rot caused by Rhizoctonia solani AG8 and R. oryzae, and Pythium root rot caused mainly by Pythium irregulare and P. ultimum. The seed treatments included Bacillus sp. L324-92, Pseudomonas fluorescens Q69c-80, Pseudomonas fluorescens Q8r1-96, difenoconazole + metalaxyl (Dividend + Apron), difenoconazole + mefenoxam (Dividend + Apron XL = Dividend XL), tebuconazole + metalaxyl (Raxil XT), and tebuconazole + thiram (Raxil-thiram). Controls were nontreated seed planted into both nontreated (natural) soil and soil fumigated with methyl bromide just prior to planting. Although the data indicate a trend in higher wheat yields with two rhizobacteria treatments over the nontreated control (171 and 264 kg/ha, respectively), these higher yields were not significantly different from the nontreated control (P = 0.06). Fungicide seed treatments alone similarly resulted in yields that were 100 to 300 kg/ha higher than the nontreated control, but only the yield responses to Dividend on winter wheat (289 kg/ha) and Dividend + Apron on spring wheat (263 kg/ha) were significant (P ≤ 0.05). The greatest yield increases over the nontreated control occurred with certain rhizobacteria-fungicide combinations, with three treatments in the range of 312 to 486 kg/ha (6.1 to 17.7%; P ≤ 0.05). Some rhizobacteria-fungicide combinations brought average yields to within 85 to 90% of those obtained with soil fumigation. Only soil fumigation produced a measurable reduction in the incidence of take-all and Rhizoctonia root rot, as assessed on washed roots. No reliable method exists for visual quantification of Pythium root rot on wheat.

scholarly journals Pseudomonas synxantha 2-79 Transformed with Pyrrolnitrin Biosynthesis Genes Has Improved Biocontrol Activity Against Soilborne Pathogens of Wheat and Canola

2020 ◽  
Vol 110 (5) ◽  
pp. 1010-1017
Author(s):  
Jibin Zhang ◽  
Dmitri V. Mavrodi ◽  
Mingming Yang ◽  
Linda S. Thomashow ◽  
Olga V. Mavrodi ◽  
...  
Keyword(s):  
Root Rot ◽  
Fusarium Culmorum ◽  
Pythium Ultimum ◽  
Gaeumannomyces Graminis ◽  
Wild Type ◽  
Wheat Roots ◽  
Recombinant Strains ◽  
Rhizoctonia Root Rot ◽  
Take All

A four-gene operon (prnABCD) from Pseudomonas protegens Pf-5 encoding the biosynthesis of the antibiotic pyrronitrin was introduced into P. synxantha (formerly P. fluorescens) 2-79, an aggressive root colonizer of both dryland and irrigated wheat roots that naturally produces the antibiotic phenazine-1-carboxylic acid and suppresses both take-all and Rhizoctonia root rot of wheat. Recombinant strains ZHW15 and ZHW25 produced both antibiotics and maintained population sizes in the rhizosphere of wheat that were comparable to those of strain 2-79. The recombinant strains inhibited in vitro the wheat pathogens Rhizoctonia solani anastomosis group 8 (AG-8) and AG-2-1, Gaeumannomyces graminis var. tritici, Sclerotinia sclerotiorum, Fusarium culmorum, and F. pseudograminearum significantly more than did strain 2-79. Both the wild-type and recombinant strains were equally inhibitory of Pythium ultimum. When applied as a seed treatment, the recombinant strains suppressed take-all, Rhizoctonia root rot of wheat, and Rhizoctonia root and stem rot of canola significantly better than did wild-type strain 2-79.

Influence of preseason weed management and in-crop treatments on two successive wheat crops. 2. Take-all severity and incidence of Rhizoctonia root rot

1993 ◽  
Vol 33 (2) ◽  
pp. 173 ◽  
Author(s):  
PTW Wong ◽  
PM Dowling ◽  
LA Tesoriero ◽  
HI Nicol
Keyword(s):  
Lower Incidence ◽  
Root Rot ◽  
The Other ◽  
High Rate ◽  
Wheat Crop ◽  
First Year ◽  
Rhizoctonia Root Rot ◽  
Heavy Grazing ◽  
Direct Drilling ◽  
Take All

The effects of cultivation and herbicide use to control weeds in wheat on wheat growth, the severity of take-all, and the incidence of rhizoctonia root rot were studied for 2 seasons. Preseason treatments were no weed control, paraquat (0.20 kg a.i./ha), glyphosate (0.18 kg a.i./ha or 4 applications of 0.72 kg a.i./ha), and heavy grazing. In-crop treatments were cultivation plus trifluralin, direct drilling plus chlorsulfuron, and direct drilling alone. At the site, take-all was the main disease while rhizoctonia root rot was relatively minor. Glyphosate applied 4 times at 0.72 kg a.i./ha over the previous spring and summer led to greater wheat dry matter (DM) production, significantly (P<0.05) less severe take-all, and a lower incidence of rhizoctonia root rot in the first year than the other preseason treatments. Spraytopping with glyphosate (0.18 kg a.i./ha) or paraquat (0.20 kg a.i./ha) and heavy grazing reduced take-all severity but not the incidence of rhizoctonia root rot. Conventional cultivation resulted in more wheat DM, significantly less severe take-all, and a lower incidence of rhizoctonia root rot than direct drilling. Grain yields reflected the trends of the DM production despite severe yield loss due to head frosting. Plots were split for cultivation and direct drilling in the second year. The highest wheat DM and grain yields were in the cultivated treatments but the effects of cultivation on take-all did not carry over from the first year. In both years, take-all was most severe in the control treatment and least severe in the treatment with the high rate of glyphosate (P<0.05). In the second wheat crop, however, take-all severity was similar in the 2 glyphosate, paraquat, and grazed treatments. The effect of a weed-free fallow obtained by use of a high rate of glyphosate was nullified in the second wheat crop because of a high carryover of volunteer wheat seedlings during the intervening wet summer. There was also a greater incidence of rhizoctonia root rot in the control than in the other treatments, and cultivation again reduced disease incidence compared with direct drilling.

scholarly journals Bacillus sp. L324-92 for Biological Control of Three Root Diseases of Wheat Grown with Reduced Tillage

1997 ◽  
Vol 87 (5) ◽  
pp. 551-558 ◽  
Author(s):  
Dal-Soo Kim ◽  
R. James Cook ◽  
David M. Weller
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
Gaeumannomyces Graminis ◽  
Limiting Factors ◽  
Bacillus Species ◽  
Bacillus Sp ◽  
Pythium Irregulare ◽  
Root Diseases ◽  
Rhizoctonia Root Rot ◽  
Take All

Strain L324-92 is a novel Bacillus sp. with biological activity against three root diseases of wheat, namely take-all caused by Gaeumannomyces graminis var. tritici, Rhizoctonia root rot caused by Rhizoctonia solani AG8, and Pythium root rot caused mainly by Pythium irregulare and P. ultimum, that exhibits broad-spectrum inhibitory activity and grows at temperatures from 4 to 40°C. These three root diseases are major yieldlimiting factors for wheat in the U.S. Inland Pacific Northwest, especially wheat direct-drilled into the residue of a previous cereal crop. Strain L324-92 was selected from among approximately 2,000 rhizosphere/rhizoplane isolates of Bacillus species isolated from roots of wheat collected from two eastern Washington wheat fields that had long histories of wheat. Roots were washed, heat-treated (80°C for 30 min), macerated, and dilution-plated on 1/10-strength tryptic soy agar. Strain L324-92 inhibited all isolates of G. graminis var. tritici, Rhizoctonia species and anastomosis groups, and Pythium species tested on agar at 15°C; provided significant suppression of all three root diseases at 15°C in growth chamber assays; controlled either Rhizoctonia root rot, takeall, or both; and increased yields in field tests in which one or more of the three root diseases of wheats were yield-limiting factors. The ability of L324-92 to grow at 4°C probably contributes to its biocontrol activity on direct-drilled winter and spring wheat because, under Inland Northwest conditions, leaving harvest residues of the previous crop on the soil surface keeps soils cooler compared with tilled soils. These results suggest that Bacillus species with desired traits for biological control of wheat root diseases are present within the community of wheat rhizosphere microorganisms and can be recovered by protocols developed earlier for isolation of fluorescent Pseudomonas species effective against take-all.

scholarly journals Biological Control of Wheat Root Diseases by the CLP-Producing Strain Pseudomonas fluorescens HC1-07

2014 ◽  
Vol 104 (3) ◽  
pp. 248-256 ◽  
Author(s):  
Ming-Ming Yang ◽  
Shan-Shan Wen ◽  
Dmitri V. Mavrodi ◽  
Olga V. Mavrodi ◽  
Diter von Wettstein ◽  
...  
Keyword(s):  
Biological Control ◽  
Pseudomonas Fluorescens ◽  
Root Rot ◽  
Gaeumannomyces Graminis ◽  
Protease Production ◽  
Ionization Mass ◽  
Soilborne Disease ◽  
Rhizoctonia Root Rot ◽  
Take All

Pseudomonas fluorescens HC1-07, previously isolated from the phyllosphere of wheat grown in Hebei province, China, suppresses the soilborne disease of wheat take-all, caused by Gaeumannomyces graminis var. tritici. We report here that strain HC1-07 also suppresses Rhizoctonia root rot of wheat caused by Rhizoctonia solani AG-8. Strain HC1-07 produced a cyclic lipopeptide (CLP) with a molecular weight of 1,126.42 based on analysis by electrospray ionization mass spectrometry. Extracted CLP inhibited the growth of G. graminis var. tritici and R. solani in vitro. To determine the role of this CLP in biological control, plasposon mutagenesis was used to generate two nonproducing mutants, HC1-07viscB and HC1-07prtR2. Analysis of regions flanking plasposon insertions in HC1-07prtR2 and HC1-07viscB revealed that the inactivated genes were similar to prtR and viscB, respectively, of the well-described biocontrol strain P. fluorescens SBW25 that produces the CLP viscosin. Both genes in HC1-07 were required for the production of the viscosin-like CLP. The two mutants were less inhibitory to G. graminis var. tritici and R. solani in vitro and reduced in ability to suppress take-all. HC1-07viscB but not HC-07prtR2 was reduced in ability to suppress Rhizoctonia root rot. In addition to CLP production, prtR also played a role in protease production.

scholarly journals Water and Temperature Parameters Associated with Winter Wheat Diseases Caused by Soilborne Pathogens

Plant Disease ◽  
2009 ◽  
Vol 93 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Richard W. Smiley
Keyword(s):  
Winter Wheat ◽  
Field Experiments ◽  
Disease Incidence ◽  
Simulation Models ◽  
Crown Rot ◽  
Yield Potential ◽  
Planting Dates ◽  
Wheat Diseases ◽  
Rhizoctonia Root Rot ◽  
Take All

Wheat in eastern Oregon is produced mostly as a 2-year rotation of winter wheat and summer fallow. Maximum agronomic yield potential is expected with early September planting dates but actual yields are generally highest for plantings made in mid-October. Field experiments with sequential planting dates from early September to December were performed over 4 years. Associations among yield, disease incidence, and 19 moisture and temperature parameters were evaluated. Incidence of Cephalosporium stripe, crown rot, eyespot, and take-all decreased as planting was delayed. Crown rot and eyespot were negatively correlated more significantly and more frequently with temperature than moisture parameters, and take-all was more associated with moisture than temperature. Rhizoctonia root rot was unrelated to planting date and climatic parameters. Crown rot was identified most frequently (4 of 5 tests) as an important contributor to yield suppression but yield was most closely associated (R2 > 0.96) with effects from a single disease in only two of five location–year tests. Yield was most related to combinations of diseases in three of five tests, complicating development of disease modules for wheat growth-simulation models.

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